WO2005038438A1

WO2005038438A1 - Method of evaluating inside of object by transmitted light

Info

Publication number: WO2005038438A1
Application number: PCT/JP2004/003078
Authority: WO
Inventors: Ken-Ichi Tanaka; Yutaka Tango; Koichi Shimmoto
Original assignee: Kose Corporation
Priority date: 2003-10-15
Filing date: 2004-03-10
Publication date: 2005-04-28
Also published as: JPWO2005038438A1; TW200513641A; JP4575296B2

Abstract

A method of evaluating the inside of an object, wherein a linearly polarized light is applied to an object, and the light passed through the object is admitted to a polarizer having a transmission axis parallel to the polarization of the applied light to detect it on the optical axis of the applied light and thereby remove a scattered light from the object, thereby obtaining an image dependent on the intensity of a transmitted light free from the effect of a scattered light. Further, a method of evaluating the inside of an object, wherein the intensity of a transmitted light is measured and computed by a plurality of wavelengths of a material contained in an object and having different absorption coefficients to thereby obtain an image emphasizing that material only, or the intensity of a transmitted light is measured with the object kept rotated to thereby obtain a 3-D light image inside the object.

Description

Evaluation method of inside of target object by transmitted light

Technical field

The present invention illuminates a target object with light, and detects light passing through the target object.

The present invention relates to a method for evaluating the inside of a target object. More specifically, it relates to a method for extracting transmitted light from which the effect of scattered light has been removed by a specific method and obtaining information focusing on a specific substance contained in the target object. The present invention relates to a method for measuring the intensity of transmitted light while rotating an object and finding out the three-dimensional structure inside the object without destroying the object.

Background art

Conventionally, as a means to obtain information on the inside of an object, slice the object and observe it using a transmission electron microscope (TEM), or observe the cut surface using an optical microscope or a scanning electron microscope (SEM) Methods have been used. However, these methods required destruction of the target object, and not only could not restore the target object, but also could not follow the change of the target object with the rubble.

To solve this problem, a method using X-ray tomography (X-ray CT) is known, but it also invades the target object, and the device must be large.

On the other hand, there is an increasing demand for nondestructive information in the target object in a minute part, that is, in real time, and this request is particularly prominent when the target object is hair.

In recent years, interest in hair coloring has increased, and coloring agents with a wide variety of colors and coloring that reduces the damage to hair during coloring 8

The importance of developing two agents and hair treatment agents for repairing the inside of hair is increasing. Therefore, it is an important technology in developing products to clarify the decolorization 'dyeing of the coloring agent actually occurring inside the hair and the repair process by hair treatment.

Normally, the effects of coloring agents and hair treatments on hair depend on time, so it was necessary to measure the effects in real time. In order to achieve this in a non-destructive and non-invasive manner, light using ordinary light as a light source can be considered in principle, but light scattered inside the object and light transmitted linearly are considered. Since a method for efficient separation has not been established, the resolution was low and there was a problem.

Therefore, it has been desired to develop a method for measuring the intensity of light transmitted linearly and imaging it, excluding light scattered inside the object. In addition, there has been a demand for the development of a method for obtaining information on minute parts using light, obtaining image information emphasizing a specific substance, and obtaining a three-dimensional structure inside a target object using light CT. Disclosure of invention

The inventor of the present invention has conducted intensive studies to solve the above-mentioned problems, and found that the target object is irradiated with linearly polarized light, and the light passing through the target object has a transmission axis parallel to the polarization of the irradiation light. I learned that scattered light and linearly transmitted light can be efficiently separated by measuring with a polarizer or by measuring the intensity of light passing through the target object by changing the wavelength of the light.

We focused on specific substances by measuring the intensity of transmitted light from which the effects of scattered light were removed, by changing the wavelength, measuring over time, or rotating the target object. The present invention was found that information was obtained or real-time information was obtained, and that three-dimensional information, that is, information inside the target object, could be obtained in a non-destructive manner. That is, the present invention irradiates the target object with linearly polarized light, applies a light having passed through the target object to a polarizer whose transmission axis is parallel to the polarization of the irradiation light, and sets c on the optical axis of the irradiation light.

It is an object of the present invention to provide a method for evaluating the inside of a target object, wherein an image dependent on the intensity of transmitted light from which the scattered light from the target object is removed by detecting using a CD camera. Another object of the present invention is to provide a method for evaluating the inside of a target object by measuring the intensity of transmitted light from which the influence of scattered light is removed while rotating the target object using a CCD camera and obtaining a three-dimensional structure inside the target object. Brief Description of Drawings

FIG. 1 is a schematic diagram of an apparatus used in the evaluation method of the present invention.

Figure 2 is a top view of the holder for setting the target object (sample).

FIG. 3 is a sectional view taken along line AA ′ of FIG.

FIG. 4 is a diagram illustrating an example of the wavelength dependence of the extinction coefficient of three types of specific substances in a target object. Fig. 5 is an explanatory diagram of the algorithm that obtains three-dimensional information by measuring while rotating the target object.

Figure 6 is an explanatory diagram of the algorithm for obtaining three-dimensional information by measuring while rotating the target object.

FIG. 7 is a diagram illustrating an imaging result for each bleach time in the first embodiment. FIG. 8 is a diagram illustrating a luminance distribution (transmitted light intensity) of RGB in the bleaching time = 0 minute in the first embodiment.

FIG. 9 is a diagram showing the distribution of melanin pigment for each bleaching time in Example 1.

FIG. 10 is a diagram showing the distribution of melanin pigments in the hair, of which the extinction coefficient has changed due to the decolorization reaction, at each bleaching time in Example 2.

FIG. 11 is a diagram illustrating the hair rotating device used in the third embodiment.

FIG. 12 is a diagram showing a three-dimensional coordinate system and poxel division used in the description of the third embodiment. It is.

The reference numerals in the drawings are as follows.

a Irradiation light side polarizing plate

b C C D Camera side polarizing plate

d, 1 e Polarization with transmission axes parallel to each other

Light source

Target object

CCD camera for transmitted light

Holder for target object set

Preparation

a 、 1 3 b · · ■ ■ Fixing glass

Void

Hair rotating device rotating part

BEST MODE FOR CARRYING OUT THE INVENTION

The present invention is directed to irradiating a target object with linearly polarized light, and detecting light passing through the target object by applying a polarizer having a transmission axis parallel to the polarization of the irradiation light on the optical axis of the irradiation light. This measures the intensity of the transmitted light, which excludes the effects of the scattered light by removing the scattered light from the target object. Although the scattered light changes slowly in a wavelength-dependent manner, the wavelength dependence of the transmitted light from which the influence of the scattered light is removed sometimes changes greatly. Therefore, measure the intensity of the transmitted light from which the influence of the scattered light is removed. Thus, the presence of a specific substance in the target object can be enhanced and obtained as an image.

More specifically, referring to FIG. 1, light emitted from the light source (2) passes through the polarizer (1a). It becomes linearly polarized light and irradiates the target object (3). The irradiation light is scattered and absorbed inside the target object, passes through the polarizer (1b) provided on the rear optical axis, and is detected by the CCD camera (4). At this time, if the polarizer (1a) and the polarizer (1b) are installed so that their transmission axes are parallel, the CCD camera (4) will transmit Therefore, an image can be obtained by transmitted light in which the influence of scattered light is eliminated.

Furthermore, as shown in Figs. 2 and 3, the target object is sandwiched between two polarizers (Id) and (1e) whose transmission axes are parallel to each other, and the target object is also irradiated with light. It is particularly preferable when the hair is small.

In addition, the intensity of scattered light generally has small wavelength dependence, and the transmitted light other than scattered light has a large wavelength dependence depending on the substance. Further, by removing the scattered light by calculation, the data of the transmitted light from which the influence of the scattered light is removed can be obtained. There are two methods for measuring the intensity of light that has passed through the target object by changing the wavelength: a method that changes the wavelength of the light irradiated to the target object and a method that changes the wavelength of the light that is detected by irradiating white light. Yes, both are suitably used. Here, when a CCD camera is used, the latter method is preferable because the light intensity can be measured at once for three channels of red, green, and blue.

It is already known to use X-rays as irradiation light, and the present invention is characterized by using light having a longer wavelength than X-rays. The wavelength of the irradiation light is preferably from 200 nm to 2000 nm. Particularly preferred is a wavelength in the visible light range.

In the present invention, the light that has passed through the target object is detected by a CCD camera, and a result that mainly depends on transmitted light from which the influence of scattered light has been removed is displayed as a two-dimensional image. It is preferable to install an objective lens on the surface because the transmittance of a small target object can be measured. The magnification of the objective lens is not particularly limited, but is preferably 5 to 800 times.

In the present invention, furthermore, the extinction coefficient of the substance contained in the target 4003078

6

Two wavelengths, i.e., either respectively irradiated at the wavelength lambda, and lambda ₂ of light in FIG. 4, or by irradiation with white light, and detects only the light of wavelength lambda and lambda _2, lambda, and lambda ₂ respectively By measuring the intensity of the transmitted light and calculating the value, it is possible to obtain information that emphasizes only the substance (a). At this time, even if a substance such as substance (b) or substance (c), which has a small difference in the absorption coefficient of light of wavelengths λ and λ ₂ , is included in the target object, the transmission at two wavelengths Since the difference in light intensity is small, it is possible to obtain an image that does not enhance the presence of the substance (b) or the substance (c).

Furthermore, since the present invention can be measured nondestructively, it is possible to measure the intensity of transmitted light of a specific wavelength over time and monitor the time change of the amount of one substance contained in the target object. At this time, it is preferable to select a wavelength at which the difference in absorbance of the substance whose time change is to be obtained is the largest.

In the present invention, the intensity of the transmitted light is measured while rotating the target object, and information on the three-dimensional structure inside the target object can be obtained.

That is, if one section of the object is divided into n X n finite elements, the scattering constant of each element (i, j) is f _d (i, j) and the absorption constant is f _a (i, j). , element (i, j) the light intensity I i _n (and j) before the parallel transmits the j direction and the light intensity after transmission I. The relationship between _ut (i, j) is expressed by equation (1) (see FIG. 5).

(j) = (/, j) x (if _d (i, j)-f _a (/, j))… h)

Here, equation (2) holds for all elements.

"',)-, ZO-1) ... (2)

Therefore, the light intensity incident on the target object is represented by I _in , and the transmitted light intensity corresponding to i is represented by I. _{Assuming that ut} (i), equation (1) can be expressed by equation (3). (0 = X (1-(j)-f _a (j))… (3) Furthermore, let the transmission constant of each element be f _t (i, j) = 1-f _d (i, j) — f _a ( i, j) ^l0 ^ o _Ut (0 = log + log f _t (, j) This calculation is performed for all i. When the angle of incidence is changed, rotate without changing the width of the incident light, Equation (4) is calculated for all the elements where each ray intersects (see Fig. 6) As a result, a simultaneous equation such as equation (5) is calculated.

(Where A is a matrix of (j 'm) X n ² (m is the number of patterns of incidence angle), and X and B are n ² order vertical vectors)

The condition is set so that j · m is larger than n 2, the Moore-Peni'ose general inverse matrix is calculated, and the solution X is obtained.

This series of operations is performed for different wavelengths, and the values of X (XA _{= a} , XA _{= b} ) are calculated. At this time, if λ whose scattering wavelength dependence is sufficiently small compared to the wavelength dependence of absorption is selected, the absorption-dependent parameter of each element can be calculated from (X _{A = a} , X, _{= b} ). Calculate and visualize the three-dimensional absorption coefficient distribution inside the target object.

By extracting the light transmission coefficient on a specific cross section of the target object from the value of the light transmission coefficient of each minute portion (each element) in the target object obtained in this way, the target object can be obtained without destruction. Cross-sectional images can also be obtained.

The method for evaluating the inside of a target object according to the present invention includes measuring the intensity of transmitted light excluding the influence of scattered light. Since measurement can be performed, image information with high resolution can be obtained. In addition, by changing the wavelength of transmitted light from which the effects of scattered light have been removed and measuring it, information can be obtained that focuses on specific substances. 1 blue report is obtained. In addition, three-dimensional information inside the target object can be obtained by rotating and measuring the target object.

The method for evaluating the inside of a target object according to the present invention is particularly suitable for measuring minute parts, and it is possible to know in real time the effects of a coloring agent and a hair treatment agent on the inside of hair. it can. Example

Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited to these Examples. Example 1

Untreated black hair was used as the target object using the target object set holder (10) shown in Figs. The target object set holder (10) is placed on the slide (11), which is commonly used for optical microscopy, with a gap of about 1 mm using fixing glasses (13a) and (13b). It consists of two fixed polarizers (1 d) and (1 e). A gap (14) of about 2 mm (width) x about 25 mm (depth) x about 1 mm (height) is formed between the two polarizers. Here, the two polarizers have transmission axes parallel to each other.

The hair was set in the holder for setting the object. For imaging, a CCD camera (DP12, manufactured by Sai-Linpass Optical Industry Co., Ltd.) equipped with an optical microscope (BX5〗, manufactured by Olympus Optical Industrial Co., Ltd.) was used. The magnification of the objective lens was〗 0. Filled voids (1 4) to bleach solution _{_{(4% H 2 0 2,}} 4% NH 3 aq), set 3078

Immediately after 3 minutes, 3 minutes, 5 minutes, 10 minutes, and 20 minutes, images were taken of the same part of the hair.

After removing the areas where hair is not visible from the obtained color image (Fig. 7), the 8-bit luminance distribution of each channel (RGB) in the image (Fig. 8) is obtained, and R _t (x, y) is obtained, respectively. ), G _t (x, y) and B _t (x, y) (where (x, y) indicates the position of the pixel in the image and t indicates the bleach time). Then, an image (Fig. 9) showing the distribution of melanin pigment inside the hair was obtained using the algorithm described below.

(Algorithm)

When t = 0, D for all (x, y). (X, y) is calculated (Equation (7)), and the maximum value is set as _Dmax .

D _t (x, y) = R _t (x, y) / G _t (x, y)

Next, after calculating D _t for all t and (x, y), M _t (x, y) normalized to 8 bits is obtained (Equation (8)).

^-^ ¹ ^ x255... ₍₈ )

max

It was possible to clearly evaluate how the black hair bleached over time. By using this method, it is possible to know in real time the effects of coloring agents and hair treatment agents on hair. Example 2

The same holder as in Example 1 was used for the sample and the target object setting holder. After the hair was set in the holder for setting the target object, imaging was performed under the same conditions as in Example 1.

After removing the area where hair is not reflected from the obtained color image, the 8-bit luminance distribution of each channel (RGB) in the image is obtained, and R _t (x, y), G _t (x, y) and B _t (xy) (where (xy) indicates the position of a pixel in the image and t indicates the bleach time). Then, using the algorithm described below, an image (Fig. 10) showing the distribution of melanin pigments inside the hair whose absorption characteristics changed due to the decolorization reaction was obtained.

(Algorithm)

When t = 20, D _t (xy) is calculated for all (xy) (Equation (9)), and the maximum value is set as D _max . When the value of D _t (xy) is less than 0, the value of D _t (xy) is 0.

D _t (x, y) = R _t (x, y) / R ₀ (x, y)

Next, after calculating D _t for all t (xy), M _t (x, y) normalized to 8 bits is obtained (Equation (1 0)) where M t (xy) is smaller than 0. Is set to 0.

M _t (x, y) = ^^-x255... _{(1 0)}

max

It was clear that the hair changed over time. By using this method, it is possible to know in real time the effects of a coloring agent and a hair treatment agent on hair. Example 3

The target object setting holder (10) shown in FIGS. 2 and 3 was used, and the same light intensity measuring device as that in Example 1 was used. The target object is hair. The hair rotation device (20) shown in Fig. 11 was used to rotate the sample hair. After setting the sample hair (21) in the holder (10) for setting the object, fill the void (14) with water and fix both ends of the hair to the center of the rotating part (22). The image was taken while rotating the hair using a rotating device (20). Rotating device supports rotating part (23) Was fixed on the microscope stage.

After removing the area where the hair is not reflected from the obtained color image, the 8-bit luminance distribution of each channel (RGB) in the image is obtained, and R (x, y, θ), G (x, y, 0) and B (x, y, 0), where (x, y) is the pixel position in the image and 0 is the hair rotation angle (Ο≤0≤2π). After that, an image showing the three-dimensional distribution of melanin pigment in the hair could be obtained using the following algorithm.

(Algorithm)

D (x, y) is calculated for all (x, y) (Equation (11)), and the maximum value is defined as D _max .

D (x, y) = R (x, y) / G (x, y)... (1 1)

Next, M (x, y) obtained by normalizing D to 8 bits is obtained (Equation (12)).

Then, the three-dimensional area including the hair is divided by a poxel having an appropriate resolution, for example, a resolution of 50 × 50 pixels in cross section and 200 pixels in length, and the set of the poxels is Q. The position of the poxel in Q is represented by (x, y, z), and the light transmission coefficient of each poxel in Q is represented by T (x, y, z) (see Fig. 12 for the coordinate system). It is assumed that each poxel is homogeneous. At this time, the logarithm of M (x, y, 0) is defined as T (x, y) at all points in Q that pass when the light imaged at point (x, y) in the image passes through the sample. , Y, z). For example, when 0 = 0, it can be expressed as equation (13).

\ ogM {x, ySi) = ^ T {x, y, z)... (1 3)

z

Similarly, for all χ, y, and 0, the obtained simultaneous equations of T are calculated using an appropriate method (eg, a method for obtaining the general inverse matrix of Moore-Pem'ose). Solve to estimate the value of T in Q. Also, y = y. Then Q The plane y == y. It is possible to obtain the T of the cross section when cut at

According to the present invention, it is possible to measure and image the intensity of light transmitted linearly, excluding light scattered inside the object, so that light can be used to obtain information on minute parts or to emphasize specific substances. Once the image information is obtained, the intensity of the transmitted light is measured while rotating the target object, and the internal three-dimensional structure can be known without destroying the target object. Also, since it is non-destructive, changes in the target object can be known in real time. Furthermore, by using hair as the target object, it is possible to clarify the decolorization and dyeing status of the coloring agent that actually occurs inside the hair, and the repair process by hair removal, which is widely used in developing such products. Available.

Claims

The scope of the claims

1. Irradiate the target object with linearly polarized light, apply a polarizer having a transmission axis parallel to the polarization plane of the irradiation light, and detect the light passing through the target object using a CCD camera on the optical axis of the irradiation light. A method for obtaining an image dependent on the intensity of transmitted light from which scattered light from the target object has been removed.

2. In the method of irradiating the target object with light and detecting the light that has passed through the target object, changing the wavelength of the light irradiating the target object or changing the wavelength of the light to be detected changes the light passing through the target object. Method for estimating the intensity of scattered light by measuring the intensity of transmitted light, and obtaining the intensity of transmitted light by calculating the scattered light from the target object.

3. The method for evaluating the inside of a target object according to claim 1 or 2, wherein the irradiation light is light having a wavelength in a range of 200 nm to 200 nm.

4. The evaluation method according to claim 1, wherein the target object is sandwiched between two polarizers whose transmission axes are parallel to each other, and the polarizer is irradiated with light from a perpendicular direction.

5. The method for evaluating the inside of a target object according to any one of claims 1 to 4, wherein the target object is hair.

6. An image in which only the substance is emphasized by measuring and calculating the intensity of the transmitted light at a plurality of wavelengths at which the absorption coefficient of the substance contained in the target object is different from each other. 6. The method for evaluating the inside of a target object according to claim 5.

7. A plurality of wavelengths with different extinction coefficients are two kinds of wavelengths with different extinction coefficients Item 6. The evaluation method inside the target object according to item 6.

8. The method according to any one of claims 1 to 7, wherein the intensity of transmitted light of a specific wavelength is measured over time, and a temporal change in an amount of the specific substance contained in the target object is monitored with an image. The evaluation method inside the target object described.

9. The method for evaluating the inside of a target object according to any one of claims 1 to 8, wherein the intensity of transmitted light is measured while rotating the target object to obtain a three-dimensional structure inside the target object.

10. A simultaneous equation consisting of multiple intensity data of transmitted light obtained by rotating the target object and measuring it is solved using a Moore-Penrose generalized inverse matrix, and each object in the target object is solved. 10. The method according to claim 9, wherein the light transmission coefficient of the minute part is obtained.

1 1. By extracting the light transmission coefficient of the minute part on the specific cross section of the target object from the value of the light transmission coefficient of each minute part in the target object, the image of the cross section without destroying the target object 10. The method for evaluating the inside of a target object according to claim 9 or claim 10, wherein: